Footwear insole

ABSTRACT

A footwear insole includes a base layer configured to overlie a sole of an article of footwear, a moisture permeable layer overlying the base layer, and an airgap structure captured between the base layer and the moisture permeable layer. Perimetric edges of the base layer, the airgap structure and the moisture permeable layer are aligned to form an insole perimetric edge.

FIELD OF THE INVENTION

The present invention relates generally to insoles for footwear.

BACKGROUND OF THE INVENTION

Insoles for footwear have long been known and used. The insole is the inside part of the shoe above the sole that runs underneath and supports the bottom of an individual’s foot. Insoles are usually easily removed and therefore, easily replaced. Insoles are often used to make a shoe more comfortable, control odor, and cushion the foot. For health-related reasons, orthotic insoles can better position and support the foot. Currently, insoles are typically fabricated of thermoplastic material, a plastic polymer that is heated and molded to the shape of the foot, providing comfort and arch support. Feet take a lot of stress, and when that stress isn’t properly absorbed it can cause injury and pain in ankles, knees and hips. Insoles are typically used to absorb shock, evenly distribute weight and provide arch support.

While generally effective for providing support, insoles do not adequately address moisture accumulation. When walking, running or otherwise moving around, people’s feet often sweat, resulting in a warm and moist environment inside the footwear. The accumulation of moisture around the feet can be detrimental to health and comfort. Control of moisture is often attempted using powders and the like.

It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art.

SUMMARY OF THE INVENTION

According to the principle of the invention, a footwear insole includes a base layer having a top surface, a bottom surface and a perimetric edge, the base layer configured to overlie a sole of an article of footwear, a moisture permeable layer having a top surface, a bottom surface and a perimetric edge, the moisture permeable layer overlying the base layer, and an airgap structure having a top surface, a bottom surface and a perimetric edge, the airgap structure captured between the base layer and the moisture permeable layer with the top surface of the airgap structure adjacent to the bottom surface of the moisture permeable layer and the bottom surface of the airgap structure adjacent to the top surface of the base layer. The perimetric edges of the base layer, the airgap structure and the moisture permeable layer are aligned to form an insole perimetric edge. In a specific aspect, stitching is spaced from and parallel to the insole perimetric edge, fastening together the base layer, the airgap layer and the moisture permeable layer. The airgap structure includes multiple layers of a mesh material, each layer having crossing strands defining apertures therethrough.

BRIEF DESCRIPTION OF THE DRAWINGS

Specific objects and advantages of the invention will become readily apparent to those skilled in the art from the following detailed description of illustrative embodiments thereof, taken in conjunction with the drawings in which:

FIG. 1 is a partial sectional side view of footwear employing an insole according to the present invention;

FIG. 2 is a top view of the insole according to the present invention;

FIG. 3 is a side view of the insole of FIG. 2 ;

FIG. 4 is an enlarged section view of a portion of the insole of FIG. 3 ; and

FIG. 5 is a top diagrammatic view of a ;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Turning now to the drawings in which like reference characters indicating corresponding elements throughout the several views, attention is directed to FIG. 1 which illustrates an article of footwear 10 including a sole 12 having an underlying heel 14 and an overlying upper portion 16. Various footwear is well known in the art and will not be described in detail herein. An insole 20, according to the present invention, is carried by article of footwear 10 overlying sole 12 and enclosed by upper portion 16 in a manner well known to insole use. While article of footwear 10 is illustrated as a shoe or boot, insole 20 can be employed with substantially any type of footwear having a sole to carry insole 20, such as athletic shoes, golf shoes, hiking boots, work boots, slippers, sandals, dress shoes, women’s shoes and men’s shoes, children’s shoes and the like. In the preferred embodiment, insole 20 is removably installable within article of footwear 10 and easily replaced. Thus, insole 20 will generally be installed after fabrication. However, one of ordinary skill in the art will understand that in some applications, insole 20 can be fixedly attached to sole 12 as a permanent or somewhat permanent element of article of footwear 10 and installed during fabrication.

Referring now to FIGS. 2 and 3 , insole 20 is typically shaped to correspond to the shape of the sole of the article of footwear into which it will be inserted. Insole 20 includes a base layer 22 on the bottom, a moisture permeable layer 24 on top and an airgap structure 26 captured therebetween. While insole 20 is preferably flat in the preferred embodiment, it can be contoured as desired, including some properties of orthotic insoles or not. The primary function of insole 20 is to cushion the foot and prevent moisture accumulation by circulation of air through airgap structure 26. Base layer 22 is a supporting layer which is preferably flat, but can be contoured, and fabricated of a material to give insole 20 a strong resilient base for support of moisture permeable layer 24 and airgap structure 26. Base layer 22 has a top surface 30, a bottom surface 31 and a perimetric edge 32. Base layer 22 is configured to overlie sole 12 with bottom surface 31 adjacent thereto, and is preferably formed of a thermoplastic material, but can be formed from foams, plastics, leather, impregnated cloth and the like.

Moisture permeable layer 24 is positioned adjacent the foot of a wearer, has a top surface 33, a bottom surface 35 and a perimetric edge 34, and allows moisture from a wearers foot to pass through toward airgap structure 26. Moisture permeable layer 24 can provide a moisture wicking characteristic, pulling moisture away from the adjacent foot, or can simply be permeable to allow quick drying. Natural and/or synthetic fibers can be used for moisture permeable layer 24, such as cotton, nylon cloth, wool cloth, mixtures and the like.

Airgap structure 26 is captured between base layer 22 and moisture permeable layer 24, and includes a perimetric edge 36, a top surface 37 and a bottom surface 38. Top surface 37 of airgap structure 26 is adjacent to bottom surface 35 of moisture permeable layer 24 and bottom surface 38 of airgap structure 26 is adjacent to top surface 30 of base layer 22. Airgap structure 26 includes a plurality of apertures through which air can circulate. Insole 20 has an insole perimetric edge 38 including vertically aligned perimetric edges 32, 34, and 36 of base layer 22, moisture permeable layer 34, and airgap structure 36, respectively. As can be seen with reference back to FIG. 2 , base layer 22, moisture permeable layer 24 and airgap layer 26 are fastened together to form insole 20 using stitching 40 adjacent to and parallel with perimetric edge 38. Stitching is employed to prevent any obstruction of airflow through perimetric edge 36 of airgap layer 26. Heat sealing, adhesives and the like can cause obstructions in perimetric edge 36 preventing airflow, and thus, preventing the proper functioning of insole 20 as will be described presently.

Turning to FIG. 4 , a portion of insole 20, indicated by broken circle A of FIG. 3 , is shown in an enlarged cross section. Insole 20 includes base layer 22 and moisture permeable layer 24 with airgap structure 26 captured therebetween as described previously. Airgap structure 26 includes multiple layers 42 of a mesh material providing a resilient structure as well as air gaps to allow airflow to remove moisture from moister permeable layer 24. With momentary reference to FIG. 5 , in the preferred embodiment, each layer 42 is a polypropylene mesh having a thickness of 0.012“ and having apertures 45 defined by crossing strands 46. Apertures 45, in the preferred embodiment, have a size of 0.014”. In this preferred embodiment, three of layers 42 are stacked to provide airgap structure 26. While three layers are used in the preferred embodiment, it will be understood that more or less can be used depending upon the thickness of each layer. The thickness of airgap structure 26 must be sufficient to ensure sufficient air flow through perimetric edge 36 to facilitate drying of moisture permeable layer 24.

As stated previously, perimetric edges 32, 34 and 36 of base layer 22, moisture permeable layer 24 and airgap structure 26, respectively, are fastened together to form insole perimetric edge 38. Fastening is accomplished using stitches 40 spaced from and parallel to perimetric edge 38. Stitching is employed, rather than using heat bonding or adhesives, to prevent clogging of apertures 45, particularly at perimetric edge 36 of airgap structure 26.

The present invention is described above with reference to illustrative embodiments. Those skilled in the art will recognize that changes and modifications may be made in the described embodiments without departing from the nature and scope of the present invention. Various changes and modifications to the embodiments herein chosen for purposes of illustration will readily occur to those skilled in the art. To the extent that such modifications and variations do not depart from the spirit of the invention, they are intended to be included within the scope thereof. 

1. A footwear insole, comprising: a base layer having a top surface, a bottom surface and a perimetric edge, the base layer configured to overlie a sole of an article of footwear; a moisture permeable layer having a top surface, a bottom surface and a perimetric edge, the moisture permeable layer overlying the base layer; an airgap structure having a top surface, a bottom surface and a perimetric edge, the airgap structure captured between the base layer and the moisture permeable layer with the top surface of the airgap structure adjacent to the bottom surface of the moisture permeable layer and the bottom surface of the airgap structure adjacent to the top surface of the base layer, and the perimetric edges of the base layer, the airgap structure and the moisture permeable layer aligned to form an insole perimetric edge.
 2. The footwear insole according to claim 1, further including stitching spaced from and parallel to the insole perimetric edge, fastening together the base layer, the airgap layer and the moisture permeable layer.
 3. The footwear insole according to claim 1, wherein the airgap structure further includes multiple layers of a mesh material, each layer having crossing strands defining apertures therethrough.
 4. The footwear insole according to claim 3 wherein each of the multiple layers of a mesh material is a polypropylene mesh having a thickness of 0.012“ and having apertures with a size of 0.014”.
 5. The footwear insole according to claim 4 wherein the multiple layers of a mesh material include at least three layers.
 6. An article of footwear comprising: a sole having a top surface; and an insole comprising: a base layer having a top surface, a bottom surface and a perimetric edge, the base layer overlying the sole with the bottom surface of the base layer adjacent to the top surface of the sole; a moisture permeable layer having a top surface, a bottom surface and a perimetric edge, the moisture permeable layer overlying the base layer; an airgap structure having a top surface, a bottom surface and a perimetric edge, the airgap structure captured between the base layer and the moisture permeable layer with the top surface of the airgap structure adjacent to the bottom surface of the moisture permeable layer and the bottom surface of the airgap structure adjacent to the top surface of the base layer, and the perimetric edges of the base layer, the airgap structure and the moisture permeable layer aligned to form an insole perimetric edge.
 7. The article of footwear according to claim 6, further including stitching spaced from and parallel to the insole perimetric edge, fastening together the base layer, the airgap layer and the moisture permeable layer.
 8. The article of footwear according to claim 6, wherein the airgap structure further includes multiple layers of a mesh material, each layer having crossing strands defining apertures therethrough.
 9. The article of footwear according to claim 8 wherein each of the multiple layers of a mesh material is a polypropylene mesh having a thickness of 0.012“ and having apertures with a size of 0.014”.
 10. The article of footwear according to claim 9 wherein the multiple layers of a mesh material include at least three layers. 